Spacecraft, such as satellites orbiting the earth, are comprised of several sub-systems. Such sub-systems may include assemblies for generating power and assemblies for communicating with ground stations and/or other spacecraft.
Spacecraft power generating sub-systems typically include one or more solar panels. For example, solar panels may be deployed on opposing sides of the main body of a spacecraft. The solar panels include photovoltaic elements that convert photonic energy (e.g. solar radiation) incident thereon to electrical energy. Electrical lines may connect the photovoltaic elements of the solar panels to other parts of the power generating sub-system, such as one or more storage batteries within the main body of the spacecraft. A portion of the electrical energy generated by the solar panels while they are exposed to solar radiation is may be stored in the batteries for later use in operating the spacecraft during times when there is not sufficient solar radiation incident on the panels for generating the electrical energy needed to operate the spacecraft.
Communications sub-systems typically include one or more antenna arrays each having a plurality of metallic antenna elements (e.g. Cu) for transmitting and/or receiving electromagnetic signals, such as radio frequency signals. These antenna arrays are typically connected by electromagnetic signal feed lines to a transmission/reception unit that is located within the main body of a spacecraft. Utilizing power from the power generating sub-system, the transmission/reception unit processes electromagnetic signals by the antenna elements and generates electromagnetic signals that are fed to the antenna elements for transmission. Given the metallic nature of the antenna array elements, known communications subsystems are often readily detectable during both periods of use and non-use.
Additionally, the solar panels of power generating sub-systems and the antenna arrays of communication sub-systems are separately constructed, supported and operated.